This invention relates to a circuit arrangement for supplying a load with energy from an alternating voltage power supply mains.
German Patent Application P 37 22 337.2, to which U.S. Pat. No. 4,821,166 corresponds, describes a circuit arrangement for transferring electric power from an alternating voltage source which is connected during given time intervals to an energy storage device for the purpose of supplying it with energy, which arrangement has a switch which is periodically activated by a control circuit for deriving the energy from an energy storage device. In this circuit arrangement high frequency disturbances produced therein are suppressed, i.e. kept away from the alternating voltage source, in that the control circuit makes the switch conducting only at times outside the time intervals in which the alternating voltage source is connected to the energy storage device. This arrangement is particularly useful in switched-mode power supplies which derive energy from a mains alternating voltage thereby generating interference voltages and currents due to the switching processes of the periodically activated switch, but which interference voltages and currents should not be introduced into the source of alternating voltage. The connection or separation of the alternating voltage source and the energy storage device is preferably effected by a rectifier stage. In the time intervals in which the rectifier stage is in the conducting state for the purpose of recharging the energy storage device, the activation of the switch is interrupted so that this switch does not introduce any interference via the conducting rectifier stage into the alternating voltage source, i.e. the mains.
However, interrupting the activation of the switch also interrupts the supply of energy to a load which is fed by the switched mode power supply so that this load is periodically and not uniformly supplied with energy.